﻿49i 
  Scientific 
  Intelligence. 
  

  

  Ferroludwigite. 
  See 
  under 
  Magnesioludwigite. 
  

  

  Griflithite. 
  E. 
  S. 
  Larsen 
  and 
  George 
  Steiger, 
  J. 
  Wash. 
  Ac. 
  

   Sc, 
  vii, 
  11, 
  1917. 
  — 
  A 
  member 
  of 
  the 
  Chlorite 
  Group. 
  Color, 
  

   dark 
  green. 
  H. 
  = 
  1. 
  Sectile. 
  G 
  = 
  2-309. 
  Fusible 
  at 
  4 
  with 
  

   intumescence 
  to 
  a 
  black 
  magnetic 
  slag. 
  Has 
  usual 
  cleavage 
  of 
  

   chlorites. 
  Occurs 
  in 
  basal 
  plates 
  and 
  shreds 
  up 
  to 
  l 
  mm 
  across. 
  

   Optically 
  — 
  . 
  2 
  V 
  from 
  0° 
  to 
  40°. 
  a 
  J_ 
  to 
  cleavage. 
  Strong 
  bire- 
  

   fringence. 
  Pleochroic; 
  a 
  pale 
  yellow, 
  b 
  olive-green, 
  c 
  brown- 
  

   green, 
  a 
  = 
  1*485 
  ± 
  "01, 
  P 
  — 
  1*569 
  ± 
  '005, 
  y 
  = 
  1-572, 
  ± 
  -005. 
  

   Comp.-4(Mg,Fe,Ca)0.(Al,Fe) 
  2 
  3 
  .5Si0 
  2 
  .7H 
  2 
  0. 
  Occurs 
  tilling 
  

   amygdaloidal 
  cavities 
  in 
  a 
  basalt 
  from 
  Cahuenga 
  Pass, 
  Griffith 
  

   Park, 
  Los 
  Angeles, 
  Cal. 
  

  

  Lorettoite. 
  R. 
  C 
  Wells 
  and 
  E. 
  S. 
  Larsen, 
  J. 
  W 
  T 
  ash. 
  Ac. 
  Sc, 
  

   vi, 
  669, 
  1916. 
  — 
  Tetragonal? 
  Occurs 
  in 
  masses 
  made 
  up 
  of 
  coarse 
  

   fibers 
  or 
  blades. 
  Perfect 
  basal 
  cleavage. 
  G. 
  = 
  7*6. 
  H. 
  = 
  3. 
  

   Fusible 
  at 
  1 
  to 
  a 
  yellow 
  crystalline 
  bead. 
  Easily 
  soluble 
  in 
  hot 
  

   dilute 
  nitric 
  acid. 
  Color 
  honey-yellow. 
  Adamantine 
  luster. 
  

   Streak 
  pure 
  yellow. 
  Uniaxial, 
  — 
  . 
  o> 
  Li 
  = 
  2*40, 
  e 
  Li 
  = 
  2-37. 
  Comp. 
  

   — 
  Probably 
  6PbO.PbCl 
  2 
  . 
  Found 
  in 
  flat, 
  compact 
  pieces 
  up 
  to 
  

   an 
  inch 
  thick, 
  apparently 
  occurring 
  in 
  thin 
  seams. 
  From 
  Loretto, 
  

   Tenn. 
  A 
  specimen 
  in 
  the 
  collection 
  of 
  the 
  University 
  of 
  Cali- 
  

   fornia 
  from 
  an 
  unknown 
  locality 
  has 
  similar 
  characters. 
  

  

  Magnesioludwigite. 
  B. 
  S. 
  Butler 
  and 
  W. 
  T. 
  Schaller, 
  

   J. 
  Wash. 
  Ac. 
  Sc, 
  viii, 
  29, 
  1917. 
  — 
  A 
  preliminary 
  announcement. 
  

   Color, 
  ivy-green. 
  Comp., 
  MgO.Fe 
  2 
  3 
  .3MgO.B 
  2 
  3 
  with 
  a 
  small 
  

   amount 
  of 
  ferrous 
  oxide 
  (2-55 
  per 
  cent) 
  replacing 
  some 
  of 
  the 
  

   magnesia. 
  Differs 
  from 
  ordinary 
  ludwigite 
  in 
  having 
  a 
  duller 
  

   luster, 
  lighter 
  color, 
  weaker 
  pleochroism 
  and 
  absorption 
  and 
  

   greater 
  translucency. 
  Found 
  associated 
  with 
  ludwigite, 
  forster- 
  

   ite 
  and 
  magnetite 
  at 
  the 
  Mountain 
  Lake 
  mine 
  at 
  the 
  head 
  of 
  Big 
  

   Cottonwood 
  Canyon, 
  south 
  of 
  Brighton, 
  Utah. 
  

  

  Suggestion 
  is 
  made 
  that 
  the 
  name 
  ludwigite 
  be 
  used 
  as 
  the 
  

   name 
  of 
  a 
  group, 
  having 
  the 
  following 
  members 
  : 
  

  

  Ferroludwigite, 
  FeO.Fe 
  3 
  3 
  .3MgO.B 
  2 
  3 
  

  

  Magnesioludwigite, 
  MgO.Fe 
  2 
  3 
  .3MgO.B 
  2 
  3 
  

   Pinakiolite, 
  MnO.Mn 
  2 
  3 
  .3MgO.B 
  2 
  3 
  

  

  Spencerite. 
  A 
  brief 
  extract 
  from 
  the 
  description 
  by 
  A, 
  H. 
  

   Phillips 
  was 
  given 
  in 
  the 
  previous 
  list. 
  The 
  original 
  description, 
  

   not 
  at 
  that 
  time 
  available, 
  was 
  by 
  W. 
  T. 
  L. 
  Walker, 
  Min. 
  Mag., 
  

   xviii, 
  76, 
  1916. 
  Additional 
  facts 
  to 
  be 
  noted 
  are 
  as 
  follows: 
  

   Probably 
  monoclinic 
  Cleavage, 
  100 
  perfect, 
  010 
  and 
  001 
  good. 
  

   /? 
  Va 
  — 
  1-6092. 
  2V 
  = 
  47° 
  54'. 
  Optically 
  — 
  . 
  Bx 
  AC 
  J_ 
  100. 
  Low 
  

   birefringence. 
  Dispersion 
  p^>v. 
  In 
  thin 
  section 
  shows 
  poly- 
  

   synthetic 
  twinning 
  on 
  100 
  with 
  extinction 
  of 
  about 
  6°. 
  Named 
  

   after 
  Mr. 
  L. 
  J. 
  Spencer 
  of 
  London. 
  

  

  